Bearing ring blanks are roughly divided into the following five types:

(1) forgings;

(2) pipes;

(3) bars (for direct cutting);

(4) coils;

(5) plates and strips.

Radial ball bearings and tapered roller bearings mostly use forgings. The reasons for using a large number of forgings are:

(1) The ductility of the metal is used to form the required size and shape, which reduces the cutting allowance. In addition, it can apply high-speed processing machines such as punching machines and rolling machines, and the productivity is high.

(2) If the shear processing surface of the bar, pipe, and plate and the bottom exhaust during processing are removed, the metal flow line of the product will not be cut off. In addition, the material strain makes the grains finer, and the work hardening improves Material strength, etc., can improve the performance of the material itself. In addition, large-diameter bearings used in wind turbines and industrial machinery must use forgings.

As for small-diameter products produced in small batches, sometimes the advantages of forgings cannot be used in terms of cost. At this time, pipes and bars can be used.
Radial ball bearings, tapered roller bearings

The forging of the inner and outer rings of radial ball bearings has the following methods: high temperature forming + cold rolling; hot forging + hot rolling; hot forging + cold rolling, etc.
High temperature forming + cold rolling